The Blues have Auckland schoolboy rugby sensation Taniela Tupou on their radar but admit they're concerned about their ability to retain him "with the world at our door trying to steal our players".

Blues coach John Kirwan said yesterday he had been to Tupou‘s last two games and was acutely aware of the 18-year-old's abilities because he plays in the same Sacred Heart first XV team as his own son.

"I see him around quite a bit, and he's definitely on our radar," said Kirwan when asked about the worldwide internet sensation they're calling the "Tongan Thor".

The 135kg Tongan-born youngster plays tighthead prop for Sacred Heart and rose to global fame when a rampaging hat-trick performance against rival Kelson Boys High was covered by Sky Television, with clips of his tries going viral.

Already there's been massive interest from Australian rugby (Tupou has family links across the Tasman) and NRL clubs, as well as from within New Zealand. And media attention has been so high that the school has shut the youngster down, declaring him off limits for all interviews.

Tupou scored another hat-trick at the weekend as his Sacred Heart side rolled to a 22-3 win over Mount Albert Grammar.

"He's a player we want to stay in the franchise," said Kirwan of the youngster who has already played at age-group level for the franchise. He's like all the other kids - there's another few boys playing for Sacred Heart - our problem is retaining these guys. We've got the world at our door trying to steal our players.

"Everyone says ‘what are you doing?' We're actually doing everything we can not to get our players stolen down the road or across the ditch. [But] it's really hard for us because we're always the ones getting attacked because we have such a big pool of players.

"We're tracking all these guys. I'd love to keep them all. Daniel (as Tupou is known by his schoolmates) was part of our Blues under-18s last year, part of our system. We're hoping he'll stay in our system, but if he gets offers from all over the place it's really hard for us to control."

Kirwan had not spoken to Tupou directly, but hoped to soon.

"He's a special athlete, and I know people in our franchise have [spoken to him] and I will be speaking to him in time. We want him to stay here."

But the former All Black great cautioned that waving contracts under the noses of every schoolboy who did something special was not a feasible way forward.

"That's the problem - we can't afford to give everyone a contract. So other people come in and pick out what they think is the cream.

"We're always the ones getting attacked, so it's very hard for us because we only have so many spots and it's very hard to protect everyone. We want to encourage these guys to stay and we do our due diligence. We are watching these guys right down to 14 or 15 [years old]."

Kirwan conceded rugby struggled to match the money that could be offered by NRL clubs looking to get youngsters on their books, and sometimes family circumstances dictated those deals were in their best interests.

"You can't keep everyone, but the hardest ones are when we've got guys going to other New Zealand franchises . . . with contracting the way is that's the business. It's just very hard for us because we've got the biggest talent pool."

Kirwan felt having transfer fees, a la football, would be the fairest way to ensure sports received fair reimbursement for time and money spent developing young players.

"If a kid's grown up here from five to 18 years old then I think we should at least get some money to put back into the schools and back into the system. Daniel is a little bit different because like a lot of young island boys, he's come in on scholarship and gets an education.

"It's pretty easy to work out: if you took a teacher's wages per annum, divide it by 30, which is the number of kids in a rugby team, it's pretty easy . . . we're talking $20-25,000 if someone has been brought up in your system from 5-18. That money can be put back in the system, so we're not investing all this money and it's all going out everywhere."

In the meantime, it seems like Kirwan would be smart to have that chat with Tupou. His son should be able to arrange it.